Aircraft: A320
Phase of flight: Climb
Anomaly: Aircraft Equipment Problem Critical

The flight crew reported for duty at about sunrise and performed their appropriate duties to prepare for passenger boarding. Neither the pilots nor flight attendants reported any abnormalities. I called Maintenance Operational Control (MOC) to clarify a date on an MEL item listed on the Flight Release to confirm it was correct; and was advised it was. Upon completion of the cockpit setup and preflight walk around by the First Officer; we completed the Preflight Checklist; I briefed the flight attendants; and then waited for the completion of boarding. Completion of boarding; pushback; engine start and taxi to the assigned departure Runway 28 was uneventful. Our position in the takeoff line up was number 3 behind two air carrier aircraft. After both departed; Tower cleared us for takeoff; I transferred control to the First Officer; who was the Pilot Flying (PF); he powered up as appropriate with a pause at 1.05 to allow the engines to spool; then proceeded to apply power to the Flex Thrust setting. No abnormalities were noted during this phase until; in retrospect; the aircraft reached the speed of 80 KIAS and the '80 Knots - Power Set' callout. I was the Pilot Monitoring (PM) and made the callout but noticed that the right engine (Engine 2) was slightly hunting for the correct power setting of approximately 1.35 EPR while the left engine had locked onto the appropriate setting. The fluctuation in the right engine was minimal; around 0.005 EPR and seemed to stabilize by 90-95 KIAS. This appeared insignificant at the time. The rest of the takeoff throughout the initial climb to 10;000 MSL was uneventful. Upon climbing past 10;000 MSL to an assigned altitude of Flight Level 230 (FL230) the aircraft was about to enter possible icing conditions therefore Engine Anti-Ice was turned ON in preparation. No abnormalities were noted and climb-out continued uneventfully until approximately 20;000 MSL where icing conditions no longer existed and the Engine Anti-Ice was turned OFF. Shortly thereafter; we were alerted by a single chime to the ECAM display indicating the following message: 'ENG 2 FUEL CTL FAULT' and subsequent action items below the title line. ATC directed us to climb to FL300; to which I responded our need to maintain this altitude because we were working a problem and would advise when able. The First Officer remained as PF; maintaining control of the aircraft and assuming communications. I began executing the ECAM actions the first of which; if I remember correctly; commanded the Thrust Lever on the affected engine be reduced to idle for 30 seconds. As we confirmed and slowly reduced the ENG 2 thrust lever; I noticed the trend arrows on the EPR gauge displayed the commanded power reduction to the new EPR TLA position (idle). I further noticed the engine initially had not spooled down completely on its own but was at a reduced power setting as compared to ENG 1. The engine then proceeded to match the idle thrust lever setting; after the 30 seconds had expired; the next ECAM Action Line commanded to return the thrust lever to the Climb Detent to presumably check the ability to control the engine. This action had no effect and ENG 2 remained at IDLE thrust. Subsequent ECAM Action command lines included placing the Engine Mode Selector to IGN/START and then shutting down the affected engine. I continued performing subsequent additional ECAM Actions of 'ENG 2 FAIL' thereby securing the engine; and confirming failed systems on the ECAM display. It was at this time the APU was started. A plan of action was devised to return to the departure airport since it was both the closest airport and closest Company airport. I re-assumed control of communications and declared an emergency to ATC and requested vectors to return to the departure airport. ATC immediately complied as did we with a turn back to the departure airport. I sent an ACARS message to Dispatch stating our condition and returning. I notified the Lead Flight Attendant ofthe aircraft status; time remaining to landing; my intent not to evacuate unless other indications led to an evacuation decision and finally that I would be making an announcement to the passengers. I then calmly made the PA announcement to the passengers informing them of what had occurred; emphasizing that the aircraft was still very safe to continue flight; and that we would be landing in 15 minutes. I finally added that the flight attendants would be giving them further instructions. After completion of all the immediate action items; the First Officer and I reviewed and completed the appropriate COM items while continuing to the airport. Descending through 10;000 MSL; I informed the flight attendants over the PA then shortly thereafter called the Lead Flight Attendant via the intercom to confirm they were indeed ready for landing and obtained an update as to the status of the passenger cabin. The lead informed me they were ready; the cabin was prepared and the passengers were calm. We finished our duties and prepared for the landing; selected Flaps 3 on the MCDU and GPWS Mode Panel on the overhead; then performed a quick review of what we had accomplished to this point. The remainder of the approach and landing occurred without incident. The landing was 'on target/on speed' and under MGLW. Fire trucks followed us down the runway as we decelerated toward the exit. We queried Ground Control regarding any other signs of damage; smoke or fire to which the reply was negative; this was also confirmed by the Fire Marshall. I announced 'Flight Attendants Stations' to keep the crew informed of my decision not to evacuate the aircraft. We continued to the gate uneventfully. Once parked and all checklist were completed. An A320 ECAM alerted ENG 2 FUEL CTL FAULT; so as the ECAM checklist was accomplished; the engine shutdown as directed; an emergency declared and the flight returned to the departure airport.